Electrically-heated boiler.



J. F. MoELROY.

ELEGTRIGALLY HEATED BOILER. APPLIOATION FILED SEPT. 16, 1908.

Patented Sept. 9, 1913.

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UNITED STATES PATENT oFF oE.

JAMES F. MQELBOY, OF ALBANY, NEW YORK, ASSIGNOR TO CONSOLIDATED CAR HEATING COMPANY, A CORPORATION OF WEST VIRGINIA.

ELECTRICALLY-HEATED BOILER.

Patented Sept.9, 1913,

App i a n fi d September 6, 1908.- Sm l-10453.25!

To all whom it may concern Be it known that I, JAMES F. MOELROY, a citizen of the United States, and a resident of the city of Albany, county of Albany, State of New York, have invented certain new and useful Improvements in Electrically-Heated Boilers, of which the following is a full, clear, and complete disclosure.

The object of my invention is to provide a boiler in which the generation of steam or vapor may be accomplished by the use of an electric current in an economical and eflicient manner, Electrically heated boilers, such as form the subject-matter of my invention, are particularly applicableto steam heating where it is desired to do away with the use of any primary means for the generation of heatgsuch as by the combustion of gas, coal or oil.

At the present time passenger cars employed. on railroads are provided with means for heating, during cold weather, by steam taken from the locomotive. Ifassene 'ger trains or cars are now not only. operated over considerable lengths of track where electric locomotives are employed solely, but such trains are also operated over tracks by the use of steam locomotives for a part of the distance, and by electric locomotives for another part of the distance. When'a train of cars, equipped with the usual steam heat-. ing apparatus and drawn by a steam locomotive, reaches \certain points where it enters What is sometimes termed the electric, zone, or that portion of the line where the electric locomotive is used, it is necessary to provide some means for heating the cars which were before heated by steam from the boiler of the steam locomotive.

One object of my invention is therefore to provide a steam boiler Which may be carried by an electric locomotive, and within which steam may bra-generated by the same electric current through which the locomotive is operated. By the application of eflicient mechanism for this purpose, the necessity of I e-equipping the cars with electric heating apparatus is obviated. In the adaptation bf my invention to the heating of -railway cars, I preferably provide a steam boiler that is mounted on a locomotive, the boiler being provided with -heating apparatus through which the electric c-urrentflows, so that steam is generated in train pipes, so that the steam generated may be used in the ordinary manner. However, I do not wish to be understood as limiting myself to this particular application of my mvention, for such electrically heated boilers may be used under other conditions and in other situations, as the occasion may demand.

Further chests and features of my in-.

vention will e apparent trom the followmg spec ficat on and the accompanying drawlngs forming a part thereof, in which-i Figure l is a longitudinal sectional view of a bo ler showmg the means for heating 'the boiler tubes; and Figs. 2, 3, 4, 5, 6, 7

and 8 are sectional views of the heating elements showing the manner of fixing and insulating the same in a boiler. Figs. 9 and 10 are respectively end and side views of the boiler tube shown in Fig. 8, also indicating the connector between two of the heating elements; Fig. 11 is a side elevation of a boiler showing the casing thereof in section and. indicating a modification comp is ng m ans where y ai is made to .circnlate through the boiler tubes,

Referrin to the drawings the numeral 1 indicates a oiler of my suit-able or preferred construction to which my invention is applied, Fig, 1 of the drawings shows a'sectiOn of a boiler, one of the boiler tubes or fines 21 being shown in section and illustrating the heating element inthe form of a tube 22 in position therein, These tubes are made of thin metal .ofthe requisite thickness to give sufficient resistance to the passage of electric current to generate the amount of heat desired in each element. These tubes-are preferably made of perforated metal as indicated at 23, althou 11 they may be made plain if desired an a lowresistance only is required. The pro rtio'n between the diameter of the boiler tu es and that of the heating element is preferably 2 to 1. For instance, where the boiler tubes are 2% inches inside diameter, the outside diameterof the heating element is preferably 1?; inches. I have shown these heating elements in the form of tubes, an it i to b und rs o that I may e other shapes according to the circumstances of individual cases. I refer to use iron as the material of which. tubesare made, such iron being pure and free from carbon. y he use o p rfo a d me a I- am a l o use a met l of a given and uni orm gag the perforations or slots in dilferent ways or I may stagger the same so that the electrict current in passing along the tube may take a zigzag course at a much greater length than if running longitudinally. The heating elements of tubes 23 being light may be supported within the boiler and within the boiler tubes by means of insulators 2 made of porcelain or other suitable material.

Although these insulators may be made of any desired form, they are preferably made with a wide, flat circumferential groove 25, in which a band 26 of crinkled or corrugated steel or other metal may be placed so as to hold the insulators centered or ,concentric with the boiler tubes, and at the same time prevent rattling therein. This construction also allows the porcelain insulators to be adapted to a boiler tube of irregular dimensions, thereby preventing unusual strains and liability of breaking where there is a variation in the diameter and cross-section of the boiler tubes.

Instead of the band of crinkled metal I -may wind the circumferential groove in the The insulators at the ends of the heatingelements, where they pass into the boiler tubes, may be made in any desirable shape to firmly hold-the heating elements in position. In Figs. 1 and 8 I have illustrated two forms of end insulators as indicated by the numerals 28 and 29. The ring insulators 24 are shown as supporting the perforated tubes inside of the boiler tube at convenient distances between the end insulators 28, and I prefer to place such ring insulators so as to have the tubes supported at points about two feet apart. The ring insulators are preferably secured in position on the heating tube by raising small round hemispheres 0r project-ions on the metal of the heating tube on each side of the ring as indicated at 30. These projections prevent the ring from sli ding longitudinally on the heating element or tubes. As indicated in Figs. 4, 7 and'8, the ring insulators may be made in two semicircular parts 31, each exactly alike, and being provided with tongues and corresponding grooves 32 at their respective ends, so that each part of the insulator will fit its correvsponding part so that the tongues and may be placed in position upon the heating element and then the heating element pushed through the boiler tube to the requisite point. The end porcelain insulators, such as indicated at 28 and 29, preferably have shoulders indicated. at 34 and 35, which rest against the ends of the boiler tubes or against the heads of the boiler. The grooves in the end porcelain insulators are preferably located some distance inward from the end of the boiler tube, because these insulators are protected from touchingthe boiler tube by the crinkled metal bands or by the ashestos cord in the circumferential groove. I thus prevent the insulator from being forced out of the boiler by any expansion of the heating element or tube, owing to the heat generated. Sufiicient space is allowed at the end of the tubes and between the outer cover or door 8 to allow expansion that may take place in the heating tubes, and I preferably further protect. the door 8 by means of insulation on its inner surface, as indicated at 36.

The heating elements within the boiler tubes may be connected in series or in parallel, or partly in series and partly in parallel, according to the voltage, amount of resistance, and the amount of heat desired. The connectors which I employ for this purpose may be of any preferred form, but in Fig. 1 I have illustrated one form of such connectors which I deem preferable. These connectors 37 are made of a bar of metal of sufficient length to extend from the end of one tube across to the end of the adjacent tubes, and is provided with holes corresponding to the relative positions of the ends of the heating elements or tubes that are to be connected. The errds of the heat ing tubes are inserted through the holes in the connecting bars 37 as indicated at 38, and the heating tube is then expanded in the holes. For this purpose I preferably use a ferrule 39 made of the same metal as the connecting bars, and this i5 forced by presving and holding the heating tube in close and continuous contact with the eye or ring in the connecting bar 37. The connecting bars, the ferrule and the heating tubes are that the same degree of expansion is prosure into the heating tube, thereby expand all preferably made of the same metal, so

duced by any change of temperature of the tubes and the surrounding air. Otherwise the contacts might become loose by the unequal expansion and consequent creeping of the parts upon each other, which would tendto loosen the contacts between the tubes and the connectors.

In Figs. 8, 9 and I0, I have shown a modification of the devices for locating the ends of the heater elements in the ends of the boiler tubes. This comprises a ring having lugs 41 adapted to contact with the 'interior of the boiler tubes and an interior flange 42 adapted to be seated in the groove in the insulator 29. This form of supporting the insulator and the ends of the heater element provides free space outside of the insulator 29 so that air may pass therethrough in addition to the passage of air through the end. of the heater element and permits a more complete circulation. This manner of supporting the end of the heaterelement is particularly adapted to the modification of the invention shown in Fig. 11.

In this form of boiler the heater elements are located in one set or portion of the tubes only, such as the tubes indicated at 44, the upper set of tubes 45 being plain and without heater elements contained therein. The ends of the boiler are provided with covers or casing 46 and 47, forming spaces through which the air may leave one set of tubes and enter the other set of tubes. A small dividing strip or partition 48 is provided within the casing 46, and in the lower space thus formed with the casing 46 is locateda fan 49, driven by a suitable motor 50. The object of the motor and fan is to force circulation of air through all the'tubes. In this way, the heated air is forced through the tubes in front of the fan and at the opposite end of the boiler beneath the casing 47 passes into the upper set of tubes and again into the space beneath the casing 46, where it is further acted upon by the fan. This arrangement causes the air to move more quickly over the heated surfaces of the heater elements? and distributes the heat evenly throughout the boiler. Inasmuch as this circulation of the air eatly increases the convection of the heat cm the heating elements to the boiler tubes, the heat passes upon. It is obvious that I do not necessarily need to locate the heating elements in this form of the invention in the tubes 44, for

they may be inclosed in a similar manner, as the air is now forced into the boiler tubes 45, the heating of the air taking place in the boiler tubes 44 and the air giving up some of its heat in. the boiler tubes 45, though in the present instance heat is also delivered to the water in the boiler through the tubes 44.

Having described this embodiment of my invention, which I at present deem preferable, I do not wish to be limited to the exact details and arrangement of parts herein setforth, for various changes may be made by persons skilled in the art without departing from the spirit and scope of my invention.

' What I desire to protect by Letters Patent of the United States is:

1. In an electrically heated boiler the compination with an air flue of a tubular metalthrough the flue and included in an electric circuit. r

2. Inan electrically heated boiler the combination with a plurality of air flues open at both ends to permit convection currents of. air, of an air chamber at one end into which said fiues open and heating elements in its several flues separated by an air space from the walls of the flue.

3. Inan electrically heated boiler the combination with an air flue open at both ends to permit longitudinal convection currents of vair of a metallic electrical heating element in the flue insulated from the interior Wall thereof and included in an electric circuit. I

4. In anelectrically heated boiler the combination with an air flue open at both ends. to permit convection currents of air of a tubular metallic heating element therein included .in an electric. circuit? .5. In an electrically heated boiler the combination with an air flue, of a tubular electric heating element therein open to permit internal convection currents of air within the element and separated by an air space from the interior wall of the flue.

6. In an electrically heated boiler, the combination with a liquid receptacle, of air fines open at both ends to permit convection eur-v rents of air and tubular heating elementsin the several flues open to permit convection elements.

7 In an electrically heated boilerythe combination with a liquid receptacle, of air fl'ues therein open at both ends to permit convection currents of air, and tubular heating elements open to permit internal air currents and separated by an air space from the walls of the flues to ermit air, currents between said heating e ements and the Walls of the tines.

' 8. In an electrically heated boiler, the combination, with a liquid receptacle, of tubes passing therethrough, electric heating devices within said tubes and; extending beyond the ends thereof, covers Lforming spaces at the endsof said receptacle, and connect- I heating element 13116113111 extending air currents in the interior of the tubular being' provided with openings to permit heated air to pass into said flue.

10-. In an electrically heated boiler the combination with a flue of a tubularheating element extending therethrough and open :at its ends, the Wall of said heating elementbeing provided with openings to permit heated air to ass into said flue, and spaced insulators for supporting said heating element within said flue.

11. In an electrically heated boiler the combination with a flue of a tubular heating element extending therethrough and open at its ends, the wall of said heating element being provided with openings to permit heated air to pass into said flue, insulators for supporting said heating element, and means for cushioning said insulators.

12. In an electrically heated'boiler, tubes passing therethrough, electric heating elements in said tubes, annular insulators between said tubes and heating elements for insulators for supporting said heating elements within said fines and provided with peripheral grooves, and cushioning means engaging said grooves.

14. In an electrically heated boiler the combination with flues passin therethrough, electric heating elements wit in said tubes, insulators for supporting said heating elements within said flues, said insulators being each formed of two members, and cushioning members for preventing separation of sald insulator members. Y

15. In an velectrically heated boiler, the combination, with a liquid receptacle, of pipes passing therethrough, an electric heating device separated from said-receptacle by an air space, and means for producing air circulation between saidv heating devices and said tubes.

16. In an electrically heated boiler, the combination, wit-h a liquid receptacle, of tubes passing therethrough, heating devices contained in a portion of said tubes, air

spaces at the ends of said tubes external to said receptacle, and means in one of said air spaces for producing air circulation between said heating devices and the walls of said tubes.

Signed at Albany, in the county of AL 'bany, this 10th day of September, 1908.

JAMES F. MGELROY.

Witnesses:

BEULAH CABLE, ERNEST D. JANsEN. 

